Class: Xanthine oxidase inhibitor
- Tablets 40 mg
- Tablets 80 mg
Decreases serum uric acid by inhibiting xanthine oxidase.
At least 49% absorbed. T max is 1 to 1.5 h. C max is approximately 1.6 mcg/mL.
Vd is 50 L. Plasma protein binding is approximately 99.2%, primarily to albumin.
Extensively metabolized by both conjugation via uridine diphosphate glucuronosyltransferase enzymes and oxidation via CYP enzymes, including CYP1A2, 2C8, and 2C9, as well as non-P450 isozymes.
Mean terminal elimination half-life is approximately 5 to 8 h. Approximately 49% is recovered in the urine and approximately 45% is recovered in the feces.
Special PopulationsRenal Function Impairment
Use with caution in patients with severe renal function impairment (CrCl 10 to 29 mL/min). Pharmacokinetics have not been studied in patients with end-stage renal function impairment who are on dialysis.Hepatic Function Impairment
Studies have not been conducted in patients with severe hepatic function impairment; use with caution.Gender
Following multiple oral doses, C max and AUC are 30% and 14% higher in women than men, respectively. However, no dosage adjustment is necessary.
Indications and Usage
Chronic management of hyperuricemia in patients with gout.
Coadministration with azathioprine, mercaptopurine, or theophylline.
Dosage and AdministrationAdults
PO Start with 40 mg once daily. The dosage may be increased to 80 mg once daily for patients who do not achieve a serum uric acid less than 6 mg/dL after 14 days.
- May be taken without regard to meals or antacid use.
Store at 59° to 86°F. Protect from light.
Drug InteractionsDrugs metabolized by xanthine oxidase (eg, azathioprine, mercaptopurine, theophylline)
Plasma concentrations of these agents may be increased, leading to toxicity. Coadministration with febuxostat is contraindicated.
Laboratory Test Interactions
None well documented.
Dizziness (at least 1%).
Abnormal LFTs (7%).
Monitor for signs and symptoms of MI and stroke. Assessment of liver function at 2 and 4 mo following the start of therapy and periodically thereafter is recommended.
Category C .
Safety and efficacy not established.
Use with caution in patients with severe renal function impairment.
Use with caution in patients with severe hepatic function impairment.
Cardiovascular thromboembolic events may occur.
Transaminase elevations more the 3 times the ULN have been reported.
May occur after initiation of treatment because of changing serum uric acid levels resulting from mobilization of urate from tissue deposits. Flare prophylaxis with NSAIDs or colchicine is recommended upon starting treatment. It may not be necessary to discontinue therapy if a gout flare occurs during treatment. Manage gout flare, as appropriate for the individual patient.
Use is not recommended in patients with a greatly increased rate of urate formation (eg, malignant disease and its treatment).
Overdosage has not been reported.
- Instruct patients to contact health care provider if they experience chest pain, rash, shortness of breath, or neurologic symptoms suggesting a stroke.
- Advise patients that product may be taken without regard to meals.
- Advise patient that concomitant prophylaxis with an NSAID or colchicine for gout flares may be used.
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